Optical transmission device and optical transmission system

Abstract

An optical transmission device includes a light output unit that outputs OSC (Optical Supervisory Channel) light, a calculator that calculates a tilt amount of a tilt occurring in a pseudo light in an optical transmission line connecting the optical transmission device and another optical transmission device facing the optical transmission device when establishing communication between the optical transmission device and the another optical transmission device based on the OSC light and the pseudo light including a wavelength band of a signal light repeated by the optical transmission device, and a controller that controls output of the pseudo light based on the tilt amount.

What is claimed is: 
     
         1 . An optical transmission device comprising:
 a light output unit that outputs OSC (Optical Supervisory Channel) light;   a calculator that calculates a tilt amount of a tilt occurring in a pseudo light in an optical transmission line connecting the optical transmission device and another optical transmission device facing the optical transmission device when establishing communication between the optical transmission device and the another optical transmission device based on the OSC light and the pseudo light including a wavelength band of a signal light repeated by the optical transmission device; and   a controller that controls output of the pseudo light based on the tilt amount.   
     
     
         2 . The optical transmission device according to  claim 1 , wherein
 the calculator calculates the tilt amount generated in either a first optical transmission line connected to a transmitter side of the optical transmission device in the optical transmission line or a second optical transmission line connected to a receiver side of the optical transmission device in the optical transmission line.   
     
     
         3 . The optical transmission device according to  claim 1 , wherein
 the calculator determines a constant optical power to be used for outputting the pseudo light based on a type of the optical transmission line, and   the controller controls output power of the pseudo light to the constant optical power.   
     
     
         4 . The optical transmission device according to  claim 1 , wherein
 the tilt includes a first tilt generated in the pseudo light in the optical transmission line based on stimulated Raman scattering, and   the calculator calculates a first tilt amount of the first tilt based on any of a type of the optical transmission line, an output power for outputting the pseudo light to the optical transmission line, a loss coefficient according to the type of the optical transmission line, and a connection loss between the optical transmission line and the optical transmission device.   
     
     
         5 . The optical transmission device according to  claim 1 , wherein
 the tilt includes a second tilt generated in the pseudo light in the optical transmission line based on a wavelength dependent loss, and   the calculator calculates a distance of the optical transmission line based on a transmission line loss of the optical transmission line and a loss coefficient corresponding to a type of the optical transmission line, and calculates a second tilt amount of the second tilt based on one of the distance and a loss value per unit distance of the wavelength dependent loss.   
     
     
         6 . The optical transmission device according to  claim 1 , wherein
 one of the optical transmission device and the another optical transmission device includes a downstream optical amplifier, and the other of the optical transmission device and the another optical transmission device includes an upstream optical amplifier, and   the calculator calculates a third tilt amount of an amplifier tilt generated in the downstream optical amplifier based on one of optical power of the pseudo light input to the downstream optical amplifier and a set value of the third tilt amount.   
     
     
         7 . The optical transmission device according to  claim 1 , wherein
 one of the optical transmission device and the another optical transmission device includes a downstream optical amplifier, and the other of the optical transmission device and the another optical transmission device includes an upstream optical amplifier, and   the calculator calculates a fourth tilt amount of an amplifier tilt generated in the upstream optical amplifier based on either optical power of the pseudo light inputted to the upstream optical amplifier or a set value of the fourth tilt amount, and transmits the OSC light including an instruction to control the output of the pseudo light based on the fourth tilt amount to one of the optical transmission device and the another optical transmission device.   
     
     
         8 . The optical transmission device according to  claim 1 , further comprising a backward pumping light source that outputs, to the optical transmission line, backward pumping light propagating in a second direction opposite to a first direction in which the OSC light propagates in the optical transmission line,
 the calculator instructing the backward pumping light source to output the backward pumping light.   
     
     
         9 . The optical transmission device according to  claim 1 , further comprising a forward pumping light source that outputs, to the optical transmission line, forward pumping light propagating in a first direction in which the OSC light propagates through the optical transmission line,
 the calculator instructing the forward pumping light source to output the forward pumping light.   
     
     
         10 . The optical transmission device according to  claim 1 , wherein a wavelength of the OSC light is longer than a wavelength of the signal light. 
     
     
         11 . The optical transmission device according to  claim 1 , wherein a wavelength of the OSC light is longer than a wavelength of the pseudo light. 
     
     
         12 . An optical transmission system comprising
 a first optical transmission device and a second optical transmission device which are opposed to each other through an optical transmission line and both repeat signal light, wherein at least one of the first optical transmission device and the second optical transmission device includes:   a light output unit that output OSC (Optical Supervisory Channel) light;   a calculator that calculates a tilt amount of a tilt occurring in a pseudo light in an optical transmission line connecting the first optical transmission device and the second optical transmission device when establishing communication between the first optical transmission device and the second optical transmission device based on the OSC light and the pseudo light including a wavelength band of the signal light; and   a controller that controls output of the pseudo light based on the tilt amount.